Insulation tubes and process of making same
OwnerRichard Gilmaninventor
Life of this patent
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Abstract
A discrete tube is provided which can be readily torn into a length of coiled insulation wrapping. The tube comprises at least two plies of a firm, foamed thermoplastic polymer web which had been set into a coiled configuration. The plies are welded together on their radially facing adjoining surfaces to form the tube, but the plies are offset and the axially facing edges of each ply are not welded together, such that the nonwelded edges form a junction line along a central portion of the radially facing edge of the adjacent ply. The tube is preferably formed by heat sealing the two plies together, while simultaneously heat setting each ply into the coiled configuration. The laminated coil resiliently maintains the desired configuration.
Claims22
An insulation tube comprising at least two welded coiled plies, each ply being formed of a web of a foamed thermoplastic mixture of resins comprising a major proportion of an ionomer and a minor proportion of a rigid thermoplastic resin having a lower tensile elastic modulus and percent elongation than the ionomer set into a coiled configuration, a radially facing surface of each web is welded to a radially facing surface of an adjoining web, but the axially facing edges on each coiled web are not welded together, adjacent plies being arranged such that the coils of one ply are offset from the coils of an adjacent ply, and a line defining the junction between the unwelded axial edges of each ply extends along the radially facing surface of an immediately adjacent ply, whereby applying a sharp axial tensile stress to the tube causes a tearing of one ply along the junction line defined by an adjacent ply so as to form a free, multi-ply coil suitable for wrapping about a pipe and the like.
Process for forming a tube capable of being readily pulled into a free helical coil, the process comprising:
- (1) heating to above the heat sealing temperature, a first web and a second web each formed of a foamed thermoplastic mixture of resins comprising a major proportion of an ionomer and a minor proportion of a rigid thermoplastic resin having a lower tensile elastic modulus and percent elongation than the ionomer;
- (2) coiling the two webs in an overlapping, offset relationship to form a multi-ply tube, each web forming one ply, and welding the adjacent surfaces of the two webs together but leaving free the transverse edges of each coiled web, whereby the unwelded junction between adjacent edges of each ply define a curved line along the radially facing surface of the adjacent ply in the tube.
An insulation tube comprising at least two welded coiled plies, each ply being formed of a web of a foamed thermoplastic mixture of resins comprising a major proportion of an ionomer and a minor proportion of a polystyrene set into a coiled configuration, a radially facing surface of each web is welded to a radially facing surface of an adjoining web, but the axially facing edges on each coiled web are not welded together, adjacent plies being arranged such that the coils of one ply are offset from the coils of an adjacent ply, and a line defining the junction between the unwelded axial edges of each ply extends along the radially facing surface of an immediately adjacent ply, whereby applying a sharp axial tensile stress to the tube causes a tearing of one ply along the junction line defined by an adjacent ply so as to form a free, multi-ply coil suitable for wrapping about a pipe and the like.
Process for forming a tube capable of being readily pulled into a free helical coil, the process comprising:
- (1) heating to above the heat sealing temperature, a first web and second web each formed of a foamed thermoplastic mixture of resins comprising a major proportion of an ionomer and a minor proportion of a polystyrene;
- (2) coiling the two webs in an overlapping, offset relationship to form a multi-ply tube, each web forming one ply, and welding the adjacent surfaces of the two webs together but leaving free the transverse edges of each coiled web, whereby the unwelded junction between adjacent edges of each ply define a curved line along the radially facing surface of the adjacent ply in the tube.
Dependencies are inferred from the claim text.